Aerial device for fire extinguishing, etc.



Bees 22, 3942 R. N. ROBERTS AERIAL DEVICE FOR FIRE EXTINGUISHING, ETC

Filed NOV. 20, 1939 IN VENTOR.

atente en. 22, ldZ

AER DEVICE FOR FIRE EXTINGUJISG, ETC.

Ronald N. Roberts, Glendale, Calif.

Application November 20, 1939, Serial No. 305,330

(Cl. 244-l36) 6 Claims.

My invention relates to the distribution of granular materials, fluids,objects and the like from the air to the earth or other surfaces below,and applies to a wide variety of useful applications including fireextinguishing, fire prevention, dusting or spraying for pest control,seeding, fertilizing, etc., etc., as well as to any art where a timed ordelayed opening parachute is useful.

A particular object of the invention is to provide for accurately timedcontrol whereby a container or the like, dropped from an airplane, orprojected by a catapult, or otherwise launched in aerial flight, may becaused to automatically stop or become retarded when at the correctaltitude and location to there release its contents in a manner tospread them over a wide area.

In fire fighting, as well as in many other arts, it has become thepractice to drop or hurl fragile bombs such as light metal cans or evenpaper bags and to depend upon their impact with the ground to burst themand distribute the contents. This method ofiers the recognized objectionthat the materials are distributed too closed to the ground andspreading depends upon prevailing Winds and is decided inefiicient; muchmaterial remaining close to the spot of impact.

It is an object of my invention to provide that a bomb or containerfalling from a given elevation will, upon reaching a predetermined lowerelevation act to release its contents in a widely distributed spray. Thedistance above the ground at which the material is to be releaseddepends upon conditions. Thus in a forest fire in tall timber a fireextinguishing or retarding chemical should be released at a higherelevation than would be the case in a grass fire pr brush fire. toprovide that the elevation at which the contents are released shall beunder control or predeterminable.

Another object of my invention is to provide an inexpensive automaticbomb, preferably devoid of explosives or expensive timing mechanisms,for carrying, releasing and distributing the material whether it begranular or fluid, and insofar as possible the bomb is to be made ofpaper, inexpensive fabric and the like; it being understood that many ofthe materials to be thus distributed are themselves quite inexpensive.

In fire fighting, mono-ammonium-phosphate is frequentlyemployed eitherin a solution or as a crystal. The solution is favored where impact andnatural winds are depended upon for It is therefore an object of theinvention distribution although it is obvious that the crystal is moreconcentrated. It is an object of the invention to provide for theefficient distribution of granular or crystalline materials such as theaforesaid phosphate, or any of the other well.

known chemicals in such form that upon reach ing a heated zone willmelt, vaporize, sublimate, or otherwise act to form a fire-extinguishingblanket of gas, vapor, fluid, slag or the like, although it will appearhereinafter that the invention permits of the distribution of wateralone.

Many other objects of my invention will appear hereinafter and will bebetter understood by reason of the order in which they appear. In theaccompanying drawing I have illustrated various devices for carrying outthe invention and while the embodiments illustrated represent some formswhich I prefer they by no means indicate a limit, the ensuing disclosuresuggesting to the minds of persons skilled in the art numerous otherways of attaining the objects of the invention.

In the drawing Figure 1 is a View mainly in side elevation of oneembodiment.

Figure 2 is a plan View thereof.

Figure 3 shows the device in operation.

Figure 4 is a plan view of the parachute.

Figure 5 is an elevation of a modification.

In carrying out my invention, the material to be distributed is placedwithin a container and launched in aerial flight or descent, as by beingdropped from an airplane. Where the material is fluid or finely dividedor granular it is readily separated fromthe container although where itmight tend to adhere to the container suitable agitating means may beprovided to loosen it at the proper time.

In any event the container is arranged so that it will travel rapidly,and it may be projected from a catapult or the like. Upon the containerhaving fallen from a given elevation, or having been in flight for agiven interval of time, a

differential is caused to be set up which results in the container beingseparated from the material and preferably retarded in flight or broughtto a complete stop.- Then, preferably by acquired energy, the materialis caused to spray itself over a wide area so that-in falling to theground or surfaces above the ground it will be efiective over a widearea.

Inwhat I believe to be the simplest embodiment for use where thematerial is dropped from a known elevation and is of a form whichreadily detaches itself from the container, I provide an elongatedtubular container having a weighted leading end, aerial fins, or thelike, which cause it to remain with its axis perpendicular in descent.When the container has reached a given point above a fire, or above theground, or above any zone to which the material is to be applied, thecontainer is suddenly retarded in flight while a lower portion or thevery bottom of the container is opened or allowed to be forced upon bythe kinetic energy acquired by the detached material. One simple devicefor so retarding the container is a timed or delayed-opening parachute.

This need not be large as the container may be of paper or pasteboardand has little total weight. When the light-weight conline form ofmono-ammonium-phosphate, for

example, air resistance will cause it to break into what appears to be acloud of dust and the individual crystals will rain down over a widearea.

The same is generally true of fluids. However in some cases it isadvisable to have slack strings or wires act to retain the bottomclosure of the container in spaced relationship to the container toprovide a distributor to better spray the material. Again where thematerial is not readily dislodged from the container or is of a natureto become packed in the container, I provide that movement of any partsuch as the parachute or the bottom closure relative to the container,during ejection, may move fingers or other agitating means thru thematerial and thus loosen it.

The formshown in Figures 1, 2 and 3 is most simple and in thisembodiment the container is indicated at 8 and is merely a paste-boardtube which may however be several inches in diameter and two or morefeet in length, although larger or smaller sizes may be employed.

This container is provided at'the upper end with a simple square ofcloth ll forming a parachute attached thereto by the shroud lines lli.

' The container is open at the lower end but this lower end is fittedwith a readily detached closure or plug l l which forms a leading endfor the bomb. The closure may be weighted or may be of the simplestlight-weight construction as required, and is preferably so lightlyfitted in place that the slightest retardation of the container willcause it to be dislodged, although in shipping and handling it is heldin place by the clips it.

The parachute may be of any fabric or even stout paper and is foldedalong the lines indicated by the numeral it to bring the comers it tothe center. first-folded form in which it is shown in Figure 4; it isprovided with reinforcements It; iii, etc.. in the form of thin rigidstrips which may be oi; thin wood, corrugated paper or the like.

Regarding the chute in this.

These are arranged to radiate from the center of the parachute as shownand to extend to or slightly beyond the lines Hi.

The container is nearly filled l1 and should this material be fluid theplug ll with'the material should be of any usual water tightconstruction, such as that of an expanding cup, although easilydislodged when released.

After the chute is folded as shown in Figure 4, the externalreenforcements are moved into parallel relationship to the container asshown in Figure 2; these strips jointly forming a polygonal sheatharound the container and being hingedly arranged by reason of beingriveted, glued, or otherwise secured in place on the parachute fabric.Each is shown provided with a normal projection I8 which forms a fin orvane to guide the device in vertical descent.

When the strips I6, l6, are so disposed there remains a space 20 betweensame and the container in which the resultant folds of the parachute aredisposed so that the parachute is totally enclosed and protected bythese strips. The strips form a. sheath of slightly increasing diameterdownwardly so that each strip becomes an airfoil having a slight angleof attack in vertical descent.

The strips are yieldably locked in this position with fingers l2projecting from each strip to support the closure l I in position,although these fingers preferably require little or no energy for theirrelease.

To yieldably hold the strips or airfoils in position, any suitable meansmay be employed, the drawings showing a simple elastic loop 22 fittedaround the assembly'near the upper ends as by being stretched over thefins. This loop may be a rubber-encased spring with a definite tensionor may be a selected. rubber band. The exact position and tensiondetermines the "timing" of the device and this is therefore subject toaccurate predetermination.

When the folded device shown in Figure 2 is launched it fallsperpendicularly and acquires great speed. As it falls each "airfoil" isreacted upon by relative wind and produces for any speed a precalculatedlift approximately normal to its plane. Thus the strips or airfoils tendto spread out or open up during descent. When 7 the device has fallen agiven distance and has acquired a given speed, this reaction overcomesthe tension of the loop 22 and the airfoils begin to spread whilehinging at their upper ends. Now the elastic loop is stretched and is soelevated with respect to the hinge points of the airfoils that itfinally acts to assist in spreading same although at the same instant itmay be entirely dislodged.

All this takes place almost instantly when a given speed is reached andthe parachute snaps open quite suddenly. Now the closure H isunsupported and when the parachute becomes effective the material in thecontainer exerts no weight on the parachute and the parachute is opposedonly by the slight mass of the container itself. Thus the relativelylarge parachute will quickly retard the container and in fact thepeculiar reaction is often such that the tube or container is actuallybrought to a stop.

Now the objects of the device have been largely attained for the bottomis wide open insofar as escape of material is concerned, and the manypounds of material continue to travel at practically uninterruptedspeed, which may be more than several hundred feet per second. Infect 33pounds of such material falling from more. than 1000 feet will have theenergy equal to one horse power operating for one minute. When materialsuch as phosphate crystals are ejected into the atmosphere .with suchacquired velocity, and with aaoasai no container to constrain them, theywill, by reaction of the static air, spread over awide area, althougheach individual crystal will have sufficient downward trend to keep itfrom being blown too far away by prevailing winds.

In this way the container is opened with considerable accuracy a givenpoint above a fire, for example, not so .close but that the material iswell sprayed over a large area and yet not so far away as to allowprevailing winds or thermals to interiere.

Of course there are a great many other arts to which this device can beapplied, particularly since it includes an accurately timed parachutedevoid of explosive charges, moving parts and the like. Where thematerial is of a nature which will not spread suitably, I provide, asshown in Figure 5, that the plug it: be attached by long string it so asto remain under the container to act as a spreader. tainer may be fittedwith the internal agitators 21 carried by either the parachute or theplug and here shown as carried by the plug.

it will be apparent now that I have provided for proiecting aconstrained mass of material in aerial flight and forits timedseparation from the container while still above the surface to which thematerial is to be applied, and for then spreading the material asrequired.

I. claim:

1. The hereindescribed method for fighting tires from the air whichconsists in dropping a receptacle containing a mass of extinguishingmaterial from an elevation above the fire, constraining the mass duringa part of the fOllOWiIlg aerial descent to allow same to acquireconsiderable velocity, and then suddenly retarding the receptacle whilereleasing the constrained mass thereby promoting its dissemination overa wide area by its reaction against the relatively static air of theatmosphere.

2. m a parachute device, a central body having a vertical axis, aplurality of vertical airfoils arranged parallel to said body and eachhinged at the upper end relative thereto and forming a sheath aroundsaid body, a parachute fabric attached to said body and disposed inspaces between said airioils and said body, and yieldable meansresponsive to a predetermined normal thrust of said airfoils acting tohold said airfoils parallel of said body until a predetermined airspeedshall have been acquired.

3. In a device of the class described, a tubular open-end container, adetachable closure fitted over the lower end thereof, a plurality ofairfoils Also if conditions require the coneach hinged at its upper endrelative to said body and each originally parallel to the axis of saidcontainer with its lower end adjacent said closure, means carried bysaid airfoils engaging said closure to temporarily retain the closure inposition, and yieldable means responsive to a given normal thrust ofsaid airfoils normally holding the airfoils parallel to said container.

4. In an aerial device for extinguishing fire, a container having anopen lower end and adapted to contain a mass of fire extinguishingmaterial which will spread out when aerially released, means associatedwiththe container for guiding it in axially vertical aerial descent,means responsive to air pressure developed when the container attains apredetermined air speed for suddenly retarding the container while inaerial descent, including a parachute attached to the container, and adetachable closure for said lower open end arranged to continue itsdescent together with the mass of material and thereby release saidmaterial due to the inertia of said mass of material and said closure,when the descent of the container is suddenly retarded.

5. In an aerial device for extinguishing fire, a container for enclosinga mass of fire extinguishing material which when aerially released willspread over a wide area, means responsive to air pressure developed whenthe descending container attains a predetermined air speed for suddenlyretarding the speed of descent of the container, and means responsive'tosaid sudden retarding of the container for causing the material tocontinue its descent due to inertia and thereby become released from thecontainer.

6. In an aerial device for extinguishing fire, a container having anopen lower end and adapted to contain a mass of fire extinguishingmaterial which will spread out when aerially released, means associatedwith the. container for guiding it in axially vertical aerial descent,means responsive to air pressure developed when the container attains apredetermined air speed for suddenly retarding the container while inaerial descent, including a parachute attached to the container; and adetachable closure for said lower open end arranged to continue itsdescent together with the mass of material and thereby release saidmaterial due to the inertia of said mass of material and said closure,when the descent of the container is suddenly retarded, and deflectormeans carried by said closure for spreading material discharging fromthe container.

RONALD N. ROBERTS.

